Flow regulators



Jan' 2, 1962 H. A. HEDLAND ETAL 3,015,341

FLOW REGULATORS 2 Sheets-Sheet 1 Filed Jan. l0. 1958 NN QN lNvNTORS H E D L AN D N "kml QN QYYMWATERMAN MM c M ATTORNEY Jan. 2, 1962 H. A. HEDLAND ETAL 3,015,341

FLOW REGULATORS Filed Jan. 10. 1958 2 Sheets-Sheet 2 FIG. 5

FLow A 26 PRESSURE t INVENTOR5 A. HEDLAND Y AQIL M. WATERMAN WMW 'tlnlted States Parent 3,015,341 FLGW REGULATGRS Harry A. Hedland, Evanston, and Paul M. Waterman,

Glenview, lll., assignors to William Waterman, Evanston, Ill.

Filed Jan. l0, 1958, Ser. No. 703,215 S Claims. (Cl. 137-493) This invention relates to liow regulators.

Flow regulators of the kind here involved control hydraulic ilow to maintain a predetermined (usually constant) rate of dow despite variations in pressure, etc. The present ow regulator embodies simple means for ermittng return or reverse flow at an unregulated rate and particularly at a rate substantially greater than maximum normal or regulated liovv. This is accomplished in a simple construction without complex 1oy-pass and check valve means.

The 'mvention may be readily understood by reference to regulator constructions embodying the invention and shown in the accompanying drawings.

ln said drawings:

FlG. l is a longitudinal section of a regulator;

HG. 2 is a cross section on the plane 2 2 of FIG. l;

FlG. 3 is a longitudinal section showing a dierent cons 'uctiong lilG. 4 is a longitudinal section of another illustrative construction; and

FlG. 5 is a diagram illustrating the improved regulation obtained by a by-pass oriice.

lilow is regulated in the illustrative device by a resilient member which is deilected by and in response to pressure to control a throttling valve which regulates liow. The latter is arranged also to be responsive to return or reverse flow and to be moved thereby to a position which permits unrestricted return or reverse llow, preferably at a rate which may if necessary be greater than maximum normal or forward flow,

Referring to the device shown in FIGS. l and 2, the resilient member is shown in the form of a spring l0 against which the throttling piston 11 acts to throttle ow through a port or ports l2. Spring 19 and piston 1l are located in and the latter is slidable in the cylindrical bore 13 of regulator housing 14.

lpiston lll is provided with ya skirt 16 adapted to bear against spring l@ and variably to throttle ports 1. ln the present instance, the skirt is provided with openings i7 adapted variably to register with ports 12, the latter being throttled by the trailing edge of ports i7 to the extent determined by spring lll in response to the duid force on piston 1l. The latter force is developed by a relatively large metering orn'ice 18 developing a relatively small pressure drop, which nevertheless is sufficient to deflect spring l@ responsively to uid pressure (actually to the dierence between upstream and downstream pressures), and thereby vaiiably to throttle ports l2 to maintain a predetermined rate oi ow (generally a constant rate o liow). Ports 12 and i7 are made large enough so that when in register yand fully opened (as occurs on reverse ow as presently explained) reverse flow may pass through the-m without restriction.

From ports l2, ilow travels through an annular passage i9 around regulator housing i4 and through ports 2l at the opposite end of the housing; and thence to outlet 22. The latter is advantageously threaded sinnilarly to inlet l5, for coupling in a line.

To adapt the regulator to a wider range of regulated flow rates, an adjusted proportion of the how may be permitted to by-pass ports l". ln the present instance, the

by-passed flow travels through bore 13 and out metering by-pass orifice 23, to join the iiow from ports 2l. Bypass orilice 23 is advantageously adjustable in size, in this case by placing it in a removable screw plug 2@ which may be changed to provide orices of dilerent sizes depending on the desired operation of the regulator.

Griiice 23 is also advantageously used to correct faulty regulation as illustrated in FIG. 5. 'ln regulators of this type there is a high velocity created adjacent the lower face of the piston lil; this can result in a low pressure area of sufficient magnitude to modify the intended force relationship between orilice pressure drop and spring force and result in a ilow curve which droops, as shown by the dotted line ZS. This may be corrected as in this case, by passing a portion of the liuid through a by-pass orifice represented by the orifice 23 separate from the regu- 1rating means. This oy-pass oriice should be or sufficient size to supplement the regulated ilow and give an aggregate rate oi flow which will be substantially uniform as represented by the solid line 26. ln other words, flow through the by-pass port supplements that through throttled ports l2 at a rate to result in a substantially uniform rate of dow independently of pressure.

As here shown in the fully retracted position (the position assumed for reverse llow), ports i7 not only register 'lully with ports l2, but supplemental discharge ports 27 are in register with supplemental discharge passages 23 in the regulator housing (see also El@ 2). Thus in addition to the metering orifice i8, reverse dow may also pass through the supplemented discharge ports 2.7. The latter ports are closed however, immediately upon resumption of normal o-r forward tlow, for the latter immediately moves the piston forward to close ports 27 and into throttling rel-'ation with ports l2. ln the illustrative device of FIG. l, this forward movement of the piston may take place freely and instantly on resumption of forward llow, for spring lll is in this instance limited in its elective length or freedom to expand (being in this instance somewhat compressed) so that the piston is initially out of operative Contact with spring l@ by a distance suicient to pennit free and unrestricted movement of the piston to operative or throttling position. As here shown the ends of spring lil are carried in spring seats 2.9 and the spring is held in pre-compressed condition by a tie rod 3l?. The spring seats 29 provide suliicient clearance in the bore 13 to permit how to pass to orice 23.

The degree of pre-compression or pre-stressing is important only as it adects the operating characteristics of the spring. These can be somewhat adjusted by screw plug 25;-, which is advantageously provided with means for adjusting it axially (in this case by a screw driver slot).

The annular passage 19 is enclosed by a shell or sleeve 3l outside of and enclosing passage l?. Its ends are sealed by G-ring packing 32 located in enlarged portions t the housing. A snap ring 33 holds the sleeve against displacement. Another snap ring Sil limits the outward movement of the piston on reverse flow land serves to register the piston ports 27 with discharge passages 28. The latter are advantageously milled in the inlet l5 at spaced points to leave lands 35 for piston ll and for the groove in which snap ring 34 is seated (FIG. 2).

The above described device embodies in a single simple unit means for permitting return how at a substantially greater rate than normal llow without separate return passages controlled by a check valve.

As illustrated in FlG. 3, a dash-pot may be added to damp out oscillations or" spring and piston under certain conditions, in this instance the spring il is limited by a tubular tie 42. which provides a passage for dow to bypass through orifice 43. This orihce is here shown Iformed in the end 44 of the housing, but it may be incorporated in a threaded plug like the plug Z4 in l. The movvable spring seat 4:53' to which tie i3 is connected, is here shown in the form of a dash-pot piston which constitutes with the bore, a dash-pot to damp out oscillations oi spring and piston. There is suiiic'ient clearance between the dash pot piston and the wall of the bore to permit the restricted backend-forth ilow involved in dash pot action. ln other respects the regulator shown in PIG. 3 is generally like that illustrated in FlGS. l and 2.

in FIG. 4 is illustrated a regulator in which the spring 5l is not limited but is in engagement with piston valve 52 in its retracted or reverse flow position. ln this regulat r there is an instant at the start of normal or forward ow, when the how besides passing through metering oriiice 53, also enters the regulator through the then open discharge passages Sil similar to passages 2S in the regulator or FIGS. l and 2. To assist in moving the piston 'to throttling position where the aforesaid discharge passages are closed to the entrance of llow, the reverse low passages 55 are inclined as shown to provide a component or force on the piston in the direction of flow to aid in moving the piston forward immediately suiiciently to cut o flow through passages Sil. The pressure drop which then develops at the metering orifice 53 is then balanced by operative deflection of spring 5l. Y rThe latter in its fully extended position shown in liG. 4 olers relatively small resistance to movement of the piston under the aforesaid component of force created by llow, withV the result lthat unregulated liow is only momentary, and the piston promptly assumes its throttling position.

A threaded by-pass plug 'like plug 24 in FlG. l is advantageously provided to permit the adjustment referred to in connection with the regulator of FlG. 1.

lt should be understood that various changes in details may be made without altering the principle of operation above described, particularly with reference to details involving simplitication of machining md assembly operations. Gbviously the invention is not limited to the details of the illustrative devices herein described, since these may be variously modified. Moreover it is not indispensable that all features of the invention be used conjointly, since various features may be used to advantage in Vdiderent combinations and sub-combinations.

Having described our invention, we claim:

l. A dow-regulator comprising in combination a housing having a cylindrical bore therein and terminal connections communicating with said bore to adapt the same for connection in a liuid line, a piston valve slidable insaid bore in response to flow through said bore, throttling ports in said bore adapted to be variably throttled by movement of said piston during normal dow in response to variations in iiuid pressure, an orince in said piston adjacent one end or said bore ,to create a pressure drop to actuate said piston, a spring adjacent the other end of said bore to balance the pressure drop force against said piston, supplemental return how ports in said bore bypassing said orice closed byY movement ofY said piston during normal ilow through, said bore being longer than the length to accommodate throttling movement of said piston by a Vdistance equivalent to the movement of the piston to jopen and close said supplemental ports, said additional length ybeing located up-stream or said throt- .tling ports whereby Yinitial movement or said piston dur- :ing normal ilow cuts od said supplemental-ports before Y throttling said throttling ports. Y

V2. A regulator Vcomprising incombination ahousing having av cylindrical bore therein and terminal connections communicating with said bore tofadapt the housing for connection in a'uid line, a piston valve slidable in said bore in response'to and in the direction ofl flow throguh said bore, a substantially large metering orice in said Vpiston adjacent the inlet terminal for creat- Ving a small pressure drop in normal flow to create a force for Vactuating Vsaid piston without substantially re- Stricting ow, throttling ports in said bore adapted to be throttled by movement of said piston in response to normal or forward flow through said bore, a spring for balancing the forceron said piston to eect throttling of said ports in response to variations of iluid pressure, said bore having additional length up-stream of the throttling position of said piston, and said piston being movable by normal llow through said additional length before it reaches throttling position, supplemental ports in said piston and in said bore in said additional length adapted to register when said piston is up-stream of its throttling position, said supplemental ports being closed and out of register when said piston moves to throttling position, said supplemental ports in said bore luy-passing said orifice to permit unrestricted reverse flow through said bore.

3. A flow regulator comprising in combination a housing having a cylindrical bore therein for iluid ow and terminal connections at each end communicating with said bore to adapt the housing for connection in a lluid line, a piston valve slidable in said bore in response to llow through said bore, a relatively large oriiice in said piston adjacent the inlet terminal for creating a relatively small pressure drop to create the force suicient for actuating said piston, throttling ports in said bore adapted to be throttled by saidY piston in response to normal or forward ilovv through said bore, a spring for balancing the force on said piston to effect throttling of said ports in response to variations of lluid pressure, said bore having supplemental ports adjacent and bypassing said oritce and up-stream of said throttling ports, said supplemental ports being controlled by said piston and being uncovered and fully opened by said piston when the latter is at the upstream end of said bore, said spring being limited in length to limit its operative engagement with said pistou to allow the latter free forward movement independent of said spring from the position Where said supplemental ports are fully opened to a position in operative throttling relation to said spring and said throttling ports, and said bore having a length to kaccommodate the throttling movement of said piston plus VadditionalV length equivalent to said free forward movement, whereby said supplemental ports are closed before said piston throttles said throttling ports.

4. A ow regulator comprising in combination a housing having a cylindrical bore therein and terminal connections communicating with said bore to adapt thesame for connection in a fluid line, a piston valve slidable in said bore in response to ow through said bore, a throttling port in said bore adapted to be variably throttled by said piston inl response to variations in lluid pressure, an orifice in saidrpiston adjacent one end of said bore to create a pressure drop to'actuate said piston, a spring adjacent the other end of said bore to balance the pressure drop force against said piston, supplemental return ilow in said bore and said piston adjacent the up-stream end of said bore and uncovered by said piston and placedV 'm communication with flow through said bore when said piston is at theup-stream end of said bore, thereby to permit reverse ilow through said housing without restriction by said orifice, said bore being longer between its said supplemental port and said throttling port than the distance between the piston-supplemental port andthe throttling port of said piston so that said supplemental ports are out of register when said piston moves down-stream to throttling position in response to normal ow. Y

5. A dow regulator comprising in combination a hous- `Ving having a cylindrical .bore therein and terminal connections communicating with said bore to adapt'the same for connection in a uid line, a piston valve slidable in said Vbore in response to ow through said bore, throttling ports in said Vbore adapted to'be variably throttled a spring adjacent the other end of said bore to balance the pressure drop force against said piston, supplemental returnv ow ports in said bore and piston adapted to register when said piston is moved by return flow to the up-stream end of said bore, thereby to permit reverse flow through said housing Without restriction by said orifice, said piston being initially movable by normal 110W a distance sulcient to move said supplemental ports in piston and bore out of register, and said bore being longer than the operative length of said piston by said distance, whereby said supplemental ports are moved out of register before said piston throttles said throttling ports.

UNITED STATES PATENTS Jackson Dec. 20, Simmance Sept. 27, Kenney Get. 5, Webb May 2, Sisk Apr, 23, Presnell Sept. 24, Martin May 6, McNeill May 27, Allen May 31, 

